From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=185.246.84.56 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793624858; b=2dDh8GSSGxxrYe4h1JK0pjrNZZcHOTVLDll7BFzPxb1cjh6FgQpscC5qs9dpH+zhak0K kBI8eI+knhu4NXSHcVgbAz7ul4Eqsj9fJjFtZyTWFuTK0/tbN8+8a8Kx0h4fz1U5qpiKu 7y9iQjSWWqSnG5FBU0hIIycxrYHUb2BqCAOHY0/s0EpYrAQEF8EAQk+kG9mR41/OGSwbU Wv0bh+VGAaYxhJelGHbLi/z0BjVMG60g6YLm9V3X+utulQVBGd89TcICib7hlzsZeAV4B X5KpJnjl+3Ana47hh1ncieXyBPX6sfNudgyDZ02sg+G9adPsH8B6wr1UuH0YBvevBog== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793624858; h=DMARC-Filter:Received:Received:Received:DKIM-Signature:From:To:Cc: Subject:Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Last-TLS-Session-Version; bh=Vjtbg0ZDAhw+N1qo63UozJWX21CxJvQ/AjeOgy46flo=; b=LIcdT1s1K8TX3DKiaUOPWHh5HARwsl7KyWutfr7cawSzk+hTZyfe+gNKN8tGZFAtarAw d9oivw43gzLERB1rERi+jgwvDJWxYFGkuS25cTA8nbHuyCWtTWF3lhik2uAkTuV4Mc0kj kbdEY5fMlQTD3QsD8YsYERwJpkfWuAFKrbzpBbNqY+EDAZR7Y3XaEijxp37KOXcZGi/Vs akANDkfgdNblaEsT8e0IBdLhObH9aJ3tBxR6BZBLh0j0YXR2Vblatv1jiIiPTl1dJx3ki 8bSI3/bKBlBUCfzzClAUVo10riwKSss33Qs7PfRVCWOJJ650QyCO5qfHHGz4Ke5H5bw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=dkim header.b=yHIlMa68; arc=none smtp.remote-ip=185.246.84.56 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A111460A2601; Mon, 2 Nov 2026 13:07:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A111460A2601 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=dkim header.b=yHIlMa68 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 037561A1413; Mon, 2 Nov 2026 13:07:36 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id C5B2660750; Mon, 2 Nov 2026 13:07:35 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 5793A103290E8; Mon, 2 Nov 2026 14:07:34 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1793624855; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=Vjtbg0ZDAhw+N1qo63UozJWX21CxJvQ/AjeOgy46flo=; b=yHIlMa68boQ5jp8tGATQo8e1TT4D7y3agiH1fFAdEtIRi4BRkSqvMTAFdHrbsLjn+EIO6T +viHtie05x13KKEfNUiEhhtFs2Dy3l3V/U0HY/xXGmqnMKaCfwURBSoqOlzbIoXdSP2OCD kidDs28dXMxXh/ALGg1XsNRkovvoaDIrUAtirU47U0ZGJjMHoaIocd+ZnVgXNfS3AuWXet c+ImP2RV93qJL3Q1cn8RwZGg4RQq0sRPmbOVcvaCY81r4lzUOBaRBM/59ATExEQ1eplkkx T91LcN7A31SsTkixZQ2G4N2G6Ju7QQF/R3rTL9mMJQBl43bRkn4aYpv2/WssXQ== From: Herve Codina To: Alexandre Belloni , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Petazzoni , Herve Codina Subject: [PATCH 3/3] rtc: pcf2127: Disable the 100th counter for PCF2131 Date: Mon, 2 Nov 2026 14:07:11 +0100 Message-ID: <20261102130712.25104-4-herve.codina@bootlin.com> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261102130712.25104-1-herve.codina@bootlin.com> References: <20261102130712.25104-1-herve.codina@bootlin.com> X-Mailing-List: linux-rtc@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 The PCF2131 has a 100th counter. This counter is enabled by default but 100th seconds values are not used in the RTC subsystem. In order to save energy when the PCF2131 is powered by its battery, disable this counter. Signed-off-by: Herve Codina --- drivers/rtc/rtc-pcf2127.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c index 1bb84f72cf5f..d090e7d063c4 100644 --- a/drivers/rtc/rtc-pcf2127.c +++ b/drivers/rtc/rtc-pcf2127.c @@ -35,6 +35,7 @@ #define PCF2127_REG_CTRL1 0x00 #define PCF2127_BIT_CTRL1_POR_OVRD BIT(3) #define PCF2127_BIT_CTRL1_TSF1 BIT(4) +#define PCF2131_BIT_CTRL1_100TH_S_DIS BIT(4) /* Replace PCF2127 TSF1 bit */ #define PCF2127_BIT_CTRL1_STOP BIT(5) /* Control register 2 */ #define PCF2127_REG_CTRL2 0x01 @@ -1455,6 +1456,20 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap, ret = devm_rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg); } + /* + * PCF2131 has a 100th seconds counter enabled by default. 100th seconds + * are not used. + * + * In order to save energy when the RTC is powered by its battery, fully + * disable this counter. + */ + if (pcf2127->cfg->type == PCF2131) { + ret = regmap_set_bits(pcf2127->regmap, PCF2127_REG_CTRL1, + PCF2131_BIT_CTRL1_100TH_S_DIS); + if (ret < 0) + return ret; + } + /* * The "Power-On Reset Override" facility prevents the RTC to do a reset * after power on. For normal operation the PORO must be disabled. -- 2.56.0